NullCacheTest.java revision 1d580d0f6ee4f21eb309ba7b509d2c6d671c4044 
1/*
2 * Copyright (C) 2011 The Guava Authors
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
5 * in compliance with the License. You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software distributed under the License
10 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
11 * or implied. See the License for the specific language governing permissions and limitations under
12 * the License.
13 */
14
15package com.google.common.cache;
16
17import static com.google.common.cache.CacheTesting.checkEmpty;
18import static com.google.common.cache.TestingCacheLoaders.constantLoader;
19import static com.google.common.cache.TestingCacheLoaders.exceptionLoader;
20import static com.google.common.cache.TestingRemovalListeners.queuingRemovalListener;
21import static java.util.concurrent.TimeUnit.SECONDS;
22
23import com.google.common.cache.CacheLoader.InvalidCacheLoadException;
24import com.google.common.cache.TestingRemovalListeners.QueuingRemovalListener;
25import com.google.common.util.concurrent.UncheckedExecutionException;
26
27import junit.framework.TestCase;
28
29/**
30 * {@link LoadingCache} tests for caches with a maximum size of zero.
31 *
32 * @author mike nonemacher
33 */
34public class NullCacheTest extends TestCase {
35  QueuingRemovalListener<Object, Object> listener;
36
37  @Override
38  protected void setUp() {
39    listener = queuingRemovalListener();
40  }
41
42  public void testGet() {
43    Object computed = new Object();
44    LoadingCache<Object, Object> cache = CacheBuilder.newBuilder()
45        .maximumSize(0)
46        .removalListener(listener)
47        .build(constantLoader(computed));
48
49    Object key = new Object();
50    assertSame(computed, cache.getUnchecked(key));
51    RemovalNotification<Object, Object> notification = listener.remove();
52    assertSame(key, notification.getKey());
53    assertSame(computed, notification.getValue());
54    assertSame(RemovalCause.SIZE, notification.getCause());
55    assertTrue(listener.isEmpty());
56    checkEmpty(cache);
57  }
58
59  public void testGet_expireAfterWrite() {
60    Object computed = new Object();
61    LoadingCache<Object, Object> cache = CacheBuilder.newBuilder()
62        .expireAfterWrite(0, SECONDS)
63        .removalListener(listener)
64        .build(constantLoader(computed));
65
66    Object key = new Object();
67    assertSame(computed, cache.getUnchecked(key));
68    RemovalNotification<Object, Object> notification = listener.remove();
69    assertSame(key, notification.getKey());
70    assertSame(computed, notification.getValue());
71    assertSame(RemovalCause.SIZE, notification.getCause());
72    assertTrue(listener.isEmpty());
73    checkEmpty(cache);
74  }
75
76  public void testGet_expireAfterAccess() {
77    Object computed = new Object();
78    LoadingCache<Object, Object> cache = CacheBuilder.newBuilder()
79        .expireAfterAccess(0, SECONDS)
80        .removalListener(listener)
81        .build(constantLoader(computed));
82
83    Object key = new Object();
84    assertSame(computed, cache.getUnchecked(key));
85    RemovalNotification<Object, Object> notification = listener.remove();
86    assertSame(key, notification.getKey());
87    assertSame(computed, notification.getValue());
88    assertSame(RemovalCause.SIZE, notification.getCause());
89    assertTrue(listener.isEmpty());
90    checkEmpty(cache);
91  }
92
93  public void testGet_computeNull() {
94    LoadingCache<Object, Object> cache = CacheBuilder.newBuilder()
95        .maximumSize(0)
96        .removalListener(listener)
97        .build(constantLoader(null));
98
99    try {
100      cache.getUnchecked(new Object());
101      fail();
102    } catch (InvalidCacheLoadException e) { /* expected */}
103
104    assertTrue(listener.isEmpty());
105    checkEmpty(cache);
106  }
107
108  public void testGet_runtimeException() {
109    final RuntimeException e = new RuntimeException();
110    LoadingCache<Object, Object> map = CacheBuilder.newBuilder()
111        .maximumSize(0)
112        .removalListener(listener)
113        .build(exceptionLoader(e));
114
115    try {
116      map.getUnchecked(new Object());
117      fail();
118    } catch (UncheckedExecutionException uee) {
119      assertSame(e, uee.getCause());
120    }
121    assertTrue(listener.isEmpty());
122    checkEmpty(map);
123  }
124}
125